1. Technical Field
The present invention relates in general to an improved telecommunications system, and in particular to a method and system for prioritizing traffic channel allocation in a channel reservation system. More particularly, the present invention relates to reserving traffic channels by computing and periodically adjusting blocking thresholds. Still more particularly, the present invention relates to a method and system in which pre-assigned blocking rates are utilized in conjunction with statistically estimated traffic fluctuations to guide blocking threshold adjustments.
2. Description of the Related Art
Corresponding to the explosive growth in cellular subscriber density, radio frequency (RF) related techniques providing more efficient allocation of limited traffic channels available within a limited RF spectrum are urgently required. Priority Access Channel Assignment (PACA) is a recently conceived methodology that provides multiple level priority access to voice channels based on the designated priority level of the user. PACA is particularly useful during periods when few or no idle or unused traffic channels are available.
Channel reservation within a wireless communications subsystem is becoming increasingly necessary to alleviate problems that arise due to all mobile subscribers having equal opportunity to access available channels. An example of such a problem is that which occurs when high value subscribers require channels during periods of high blocking (during periods of free or low cost airtime, for example). A more urgent example such problems occur during emergencies, when emergency services (911 type calls, for example) are invoked.
A PACA queuing technique for providing priority access to voice channels has recently been defined in TIA-664 and in some air interface standards. PACA queuing provides a method to queue call origination requests based on priority, when there are no traffic channels (sometimes referred to as xe2x80x9cvoice channelsxe2x80x9d) available. This method often includes delivering a reply message to the user indicating that the request is queued and its queue position.
There are several problems with current implementations of PACA. First, PACA addresses and implements prioritization only after all voice channels have been assigned, thus causing a delay in service to a potentially high priority user. Another problem with PACA is that is does not provide the ability to queue termination access requests nor does it address handling of intersystem handoff of calls queued. In addition, implementation of PACA often results in increased control channel messaging (especially on the forward control channel), potentially impacting other telecommunications services.
The demand for a workable solution to the shortcomings of conventional traffic channel priority allocation may increase for many reasons including: government regulations and recommendations for providing enhanced emergency services, especially during crisis situations; promotional and competitive offers by Service Providers to offer low or free air time; increased number of mobile subscribers; and, competition among Service Providers that offer some form of priority service.
It can therefore be appreciated that a need exists to address the problem of all mobile subscribers having equal access to traffic channels regardless of congestion or priority. Providing different levels of access to voice channels based on a priority pre-assigned to the subscriber would permit subscribers/users to receive the benefit of a multilevel prioritization in a wireless communications network.
It is therefore one object of the present invention to provide a method and system for prioritizing traffic channel allocation in a channel reservation system.
It is another object of the present invention to provide a method and system for reserving traffic channels by computing and dynamically adjusting blocking thresholds.
It is yet another object of the present invention to provide a method and system in which pre-assigned blocking rates are utilized in conjunction with statistically estimated traffic fluctuations to guide blocking threshold adjustments.
The above and other objects are achieved as is now described. A method and system are disclosed for providing priority access channel allocation within a telecommunication subsystem in which channel access requests are categorized within a prioritization system that includes a first priority level, and a second priority level which is lower in priority with respect to the first priority level. A targeted blocking rate is first assigned to the first priority level. During active operation of the telecommunication subsystem, a statistical estimation of actual traffic intensity experienced by the first priority level is performed. Thereafter, the targeted blocking rate and estimated traffic intensity are utilized in computing a blocking threshold for the first priority level. This blocking threshold defines a number of channels, n, to which access by the second priority level will be blocked, such that the first priority level may achieve its assigned targeted blocking rate.